That would work, but you end up with a lot of overlap since button shapes are square. I thought about using a circle on tap and placing within the country, but you still loose a little tappable real-estate depending on the shape of the country.

If you drag a button into your scene, then left click the button icon in the Properties panel, you get the Image Button option. After selecting that option, you’ll see an Images pane appear lower down in properties; here, you can navigate to the images you want to use for Released and Pressed states in your Content Library (could be the same image, obviously). This way, you’re not dealing with polygons but with whatever images–including maps of African countries–you choose. Hope this helps.

Here is a possible solution that worked for us when we had to create rounded interactive areas and a player in the middle. We replicated and overlapped rectangular buttons to cover the clickable surfaces and made the buttons transparent.